Asus Tinker

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-90 on the third isn't too bad for the integrated.

Anyone done multichannel on this guy yet? I haven't dug into the documentation to see if we can slave 6 channels on to the GPIO/I2S or if it has to be done via USB.

The Allo Piano 2.1 has two i2s-capable DAC chips driving four channels -2 left, 2 right. No idea how they are managing that, whether both DACs are receiving the same stream or whether all four channels are on separate serial streams.
 
-90 on the third isn't too bad for the integrated.

Anyone done multichannel on this guy yet? I haven't dug into the documentation to see if we can slave 6 channels on to the GPIO/I2S or if it has to be done via USB.

Not sure where you are getting your numbers, but the 3rd order distortion for the integrated sound codec on the Tinker board was 0.0223% in my measurement, which translates to -73dB with respect to the fundamental. Also the total noise floor is only down 73dB below the fundamental level (0.0483%-0.0250%=0.0233%, or -72.65dB). These number are pretty crappy for a DAC. OK for casual headphone listening perhaps.

In the other plot, presented as a comparison, the 3rd order distortion of an inexpensive ES9023 USB dongle was -107dB (0.0004%) and the total noise was about -85dB below (0.0055%). Also, the maximum output level is higher by over 10dB, meaning it can drive amps with over 1V input sensitivity. All in all this is a good DAC for the price (which was way under $50 for a populated PCB).
 
All good. :) And usually I distrust the %age numbers as they can be easily monkeyed with depending on bin width.

In searching around, looks like there's only one stereo I2S arrangement. Not sure if some of the other pins can be thus reconfigured. Might make more sense/simpler to pipe it all through USB.
 
The Allo Piano 2.1 has two i2s-capable DAC chips driving four channels -2 left, 2 right. No idea how they are managing that, whether both DACs are receiving the same stream or whether all four channels are on separate serial streams.

From what I gathered whilst mooting 2xPlainAMP etc a year or so ago....

I2S on the Pi is 2 channel output.
It is possible to I2C address DACs or AMPs via bus address (0/1 that I know of) to program/load different DSP into each DAC/DSP/AMP.
PlainAMP had a jumper to select bus address if running two in parallel. I guess Piano 2.1 has it controlled on the board.

So each DAC gets the whole stereo signal sent to it. The DSP decides what to do with it after that.

J.
 
The point being made is that we have this lovely microcontroller already, and you have to figure out a means of breaking up a 8-channels I2S stream into 4 stereo I2S streams to interface with at least any of TI's, Cirrus's, or AKM's DACs (I just checked DS's). It'd be nice to not have to use another layer of glue to get the job done.
 
I2S is not, as you say, "2 channel". I2S is a hardware communication bus. What data you send over that hardware is determined by the software interacting with the I2S bus on either "end". You can send and receive lots of audio channels if you want - just check out the "Octo Pi soundcard" from Audio Injector for an example.

Ah, not so much of a hardware or microcode limitation then.... More of an OS or driver thing if there's a limit anywhere?
 
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Hand waving? What do you want from me? The guy asked if there were any dac for the tinker board. I saw this article prior to the question being asked. I provided a link. There aren't that many dacs for this single board computer.

The tinker and the dac are newer products. Contact the manufacturer is you've want data.
 
My point was that the link you gave led to a page that was long on praise but short on actual data, measurements, etc. How should I trust it?

The Tinker board can use virtually any linux compatible class-compliant USB DAC. There are many in this category. No need for special HATs and drivers that might go obsolete when the OS updates...
 
Hey man, chill out. I didn't mean it as an attack on YOU but on the web page you linked to. Maybe my reaction was a little harsh, but I am so sick of flashy products like this for audio that have very little if any information, or give specs by quoting the manufacturer data sheet instead of taking actual measurements of their particular implementation of the IC. (HINT: often times performance is worse). That's what popped into my head when I opened your link.

So I did my "research". Here is the link to the product at the seller:
DACBerry ONE for Raspberry Pi A+/B+/2B/3B – OSA Electronics
Specs? Nothing, except "Up to 384kHz / 32bit resolution". So what? It might be good. It might be crap. Who knows - there is no data provided. But it looks shiny and cool and cost only 50 Euros. So go for it if you like.
 
Just got a Tinker Board on eBay for $53 with shipping. So in a few days will load Volumio on it and via its USB outlet connect to my Emotiva DAC and tell you what I think. If that does not produce quality sound, I will look for a compatible SPDIF out HAT.
 
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